The semiconductor integrated circuit (IC) industry has experienced exponential growth. Technological advances in IC materials and design have produced generations of ICs where each generation has smaller and more complex circuits than the previous generation. In the course of IC evolution, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometry size (i.e., the smallest component (or line) that can be created using a fabrication process) has decreased. This scaling down process generally provides benefits by increasing production efficiency and lowering associated costs. Such scaling down has also increased the complexity of processing and manufacturing ICs and, for these advances to be realized, similar developments in IC processing and manufacturing are needed.
One development in the scaling down process is the use of fin-type field effect transistors (FinFETs). It is desired to further improve the operation of FinFETs, such as by using a gate all around (GAA) transistor structure to increase the efficiency of gate control over the transistor channel. The GAA structure is typically formed on a silicon-on-nothing (SON) substrate, and is not self-aligned. This can result in a high source and drain resistance and further loss performance. Accordingly, what is needed is a device for improving the fabrication and operation of the FinFET.